In Minnesota, the oat crop is used for either grain and straw or as a nurse crop for seeding legumes. The recommendations in the tables that follow are intended for situations where the crop is grown for grain and straw.
We base nitrogen (N) fertilizer guidelines can on the results of the soil (NO3--N) test or the consideration of the combination of expected yield, previous crop, and soil organic matter content. The soil nitrate test is appropriate for western Minnesota (see Figure 1).
This is the equation for fertilizer N guidelines with the soil nitrate test.
Nrec = (1.3) (EY) - STN(0-24 in.) - NPc
EY = expected yield (lb./acre)
STN = nitrate-nitrogen (NO3--N) measured to a depth of 24 in. (lb./acre)
Npc = amount of N supplied by the previous legume crop (lb./acre).
Table 1 lists the N fertilizer guidelines for situations where the soil NO3--N test is not used. Apply the suggested rate of N fertilizer before planting. All sources of fertilizer should have an equal effect on yield.
Nitrogen, when needed, can come from several sources. If applied in a way to prevent loss, all sources of nitrogen have an equal effect on yield. When using either dry or liquid sources, the fertilizer N can be broadcast and incorporated before planting. If anhydrous ammonia is the preferred source, knife in the fertilizer before planting.
Table 1: Nitrogen fertilizer guidelines
|Crop grown last year||Organic matter level*||Expected yield: 40-60 bushels per acre||Expected yield: 61-80 bushels per acre||Expected yield: 81-100 bushels per acre||Expected yield: 101-120 bushels per acre||Expected yield: 120 + bushels per acre|
|Alfalfa (4+ plants per square foot)||Low||0 lbs. (N/acre)||0 lbs. (N/acre)||0 lbs. (N/acre)||0 lbs. (N/acre)||0 lbs. (N/acre)|
|Alfalfa (4+ plants per square foot)||Medium and high||0 lbs.||0 lbs.||0 lbs.||0 lbs.||0 lbs.|
|Alfalfa (2 to 3 plants per square foot)||Low||0 lbs.||0 lbs.||20 lbs.||40 lbs.||60 lbs.|
|Alfalfa (2 to 3 plants per square foot)||Medium and high||0 lbs.||0 lbs.||10 lbs.||30 lbs.||50 lbs.|
|Soybeans Alfalfa (1 or fewer plants per square foot)||Low||0 lbs.||20 lbs.||40 lbs.||60 lbs.||80 lbs.|
|Soybeans Alfalfa (1 or fewer plants per square foot)||Medium and high||0 lbs.||0 lbs.||30 lbs.||50 lbs.||70 lbs.|
|Edible beans, field peas||Low||20 lbs.||40 lbs.||60 lbs.||80 lbs.||100 lbs.|
|Edible beans, field peas||Medium and high||10 lbs.||30 lbs.||50 lbs.||70 lbs.||90 lbs.|
|Group 1 crops||Low||0 lbs.||0 lbs.||0 lbs.||25 lbs.||45 lbs.|
|Group 1 crops||Medium and high||0 lbs.||0 lbs.||0 lbs.||15 lbs.||35 lbs.|
|Group 2 crops||Low||40 lbs.||60 lbs.||80 lbs.||100 lbs.||120 lbs.|
|Group 2 crops||Medium and high||30 lbs.||50 lbs.||70 lbs.||90 lbs.||110 lbs.|
* low = less than 3.0%; medium and high = 3.0% or more.
Use these recommendations for oat production when the soil NO3--N test isn’t used.
Crops in Group 1:
Alsike clover, birdsfoot trefoil, grass/legume hay, grass legume pasture, fallow and red clover.
Crops in Group 2:
Barley, buckwheat, canola, corn, grass hay, grass pasture, oat, potato, rye, sorghum-sudan, sugarbeet, sunflower, sweet corn, triticale and wheat.
Phosphate, potash and other nutrients
The rates listed are appropriate for both broadcast and banded (drill applied) application. There is no research evidence with this crop to suggest that the banded placement is more efficient than a broadcast application.
Use one of the following equations if you want a phosphate guideline for a specific soil test and a specific expected yield:
P2O5 rec = [0.644 - (0.032) (Bray P in ppm)] (Expected yield)
P2O5 rec = [0.644 - (0.041) (Olsen P in ppm)] (Expected yield)
Table 2: Phosphate fertilizer guidelines
|Expected yield||0-5 parts per million (ppm) Bray and 0-3 ppm Olsen||6-10 ppm Bray and 4-7 ppm Olsen||11-15 ppm Bray and 8-11 ppm Olsen||16-20 ppm Bray and 12-15 ppm Olsen||21+ ppm Bray and 16+ ppm Olsen|
|40-60 (bu/ac)||30 lbs. (P2O5/acre)||20 lbs. (P2O5/acre)||10 lbs. (P2O5/acre)||0 lbs. (P2O5/acre)||0 lbs. (P2O5/acre)|
|61-80||40 lbs.||30 lbs.||15 lbs.||0 lbs.||0 lbs.|
|81-100||50 lbs.||35 lbs.||20 lbs.||0 lbs.||0 lbs.|
|101-120||60 lbs.||45 lbs.||25 lbs.||10 lbs.||0 lbs.|
|121+||70 lbs.||50 lbs.||30 lbs.||10 lbs.||0 lbs.|
Use the following equations if you want a potash guideline for a specific soil test and a specific expected yield:
K2O rec = [1.2773 - (0.0086) (Soil test K in ppm)] (Expected yield)
Table 3: Potash fertilizer guidelines
|Expected yield||K soil test: 0-40 parts per million (ppm)||K soil test: 41-80 ppm||K soil test: 81-120 ppm||K soil test: 121-160 ppm||K soil test: 161+ ppm|
|40-60 (bu/ac)||55 lbs. (K2O/acre)||40 lbs. (K2O/acre)||20 lbs. (K2O/acre)||0 lbs. (K2O/acre)||0 lbs. (K2O/acre)|
|61-80||75 lbs.||55 lbs.||30 lbs.||0 lbs.||0 lbs.|
|81-100||95 lbs.||70 lbs.||40 lbs.||0 lbs.||0 lbs.|
|101-120||115 lbs.||85 lbs.||45 lbs.||10 lbs.||0 lbs.|
|121+||130 lbs.||90 lbs.||50 lbs.||10 lbs.||0 lbs.|
Except for the need for sulfur (S) when this crop is grown on sandy soils, other nutrients are not needed in a fertilizer program. For production on sandy soils, either use 10-12 lb. S/acre with the drill at planting or broadcast 25 lb. S/acre and incorporate before planting.
CAUTION! Do not apply more than 20 lb. N per acre as urea (46-0-0) with the drill. Do not place ammonium thiosulfate (12-0-0- 26) in direct contact with the seed. Do not place fertilizers containing boron in direct contact with the seed.
Reviewed in 2018